1 /* 2 * linux/arch/sh/kernel/irq.c 3 * 4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 5 * 6 * 7 * SuperH version: Copyright (C) 1999 Niibe Yutaka 8 */ 9 #include <linux/irq.h> 10 #include <linux/interrupt.h> 11 #include <linux/module.h> 12 #include <linux/kernel_stat.h> 13 #include <linux/seq_file.h> 14 #include <asm/processor.h> 15 #include <asm/machvec.h> 16 #include <asm/uaccess.h> 17 #include <asm/thread_info.h> 18 #include <cpu/mmu_context.h> 19 20 atomic_t irq_err_count; 21 22 /* 23 * 'what should we do if we get a hw irq event on an illegal vector'. 24 * each architecture has to answer this themselves, it doesn't deserve 25 * a generic callback i think. 26 */ 27 void ack_bad_irq(unsigned int irq) 28 { 29 atomic_inc(&irq_err_count); 30 printk("unexpected IRQ trap at vector %02x\n", irq); 31 } 32 33 #if defined(CONFIG_PROC_FS) 34 /* 35 * /proc/interrupts printing: 36 */ 37 static int show_other_interrupts(struct seq_file *p, int prec) 38 { 39 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 40 return 0; 41 } 42 43 int show_interrupts(struct seq_file *p, void *v) 44 { 45 unsigned long flags, any_count = 0; 46 int i = *(loff_t *)v, j, prec; 47 struct irqaction *action; 48 struct irq_desc *desc; 49 50 if (i > nr_irqs) 51 return 0; 52 53 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) 54 j *= 10; 55 56 if (i == nr_irqs) 57 return show_other_interrupts(p, prec); 58 59 if (i == 0) { 60 seq_printf(p, "%*s", prec + 8, ""); 61 for_each_online_cpu(j) 62 seq_printf(p, "CPU%-8d", j); 63 seq_putc(p, '\n'); 64 } 65 66 desc = irq_to_desc(i); 67 if (!desc) 68 return 0; 69 70 spin_lock_irqsave(&desc->lock, flags); 71 for_each_online_cpu(j) 72 any_count |= kstat_irqs_cpu(i, j); 73 action = desc->action; 74 if (!action && !any_count) 75 goto out; 76 77 seq_printf(p, "%*d: ", prec, i); 78 for_each_online_cpu(j) 79 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 80 seq_printf(p, " %14s", desc->chip->name); 81 seq_printf(p, "-%-8s", desc->name); 82 83 if (action) { 84 seq_printf(p, " %s", action->name); 85 while ((action = action->next) != NULL) 86 seq_printf(p, ", %s", action->name); 87 } 88 89 seq_putc(p, '\n'); 90 out: 91 spin_unlock_irqrestore(&desc->lock, flags); 92 return 0; 93 } 94 #endif 95 96 #ifdef CONFIG_IRQSTACKS 97 /* 98 * per-CPU IRQ handling contexts (thread information and stack) 99 */ 100 union irq_ctx { 101 struct thread_info tinfo; 102 u32 stack[THREAD_SIZE/sizeof(u32)]; 103 }; 104 105 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 106 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 107 #endif 108 109 asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs) 110 { 111 struct pt_regs *old_regs = set_irq_regs(regs); 112 #ifdef CONFIG_IRQSTACKS 113 union irq_ctx *curctx, *irqctx; 114 #endif 115 116 irq_enter(); 117 irq = irq_demux(irq); 118 119 #ifdef CONFIG_IRQSTACKS 120 curctx = (union irq_ctx *)current_thread_info(); 121 irqctx = hardirq_ctx[smp_processor_id()]; 122 123 /* 124 * this is where we switch to the IRQ stack. However, if we are 125 * already using the IRQ stack (because we interrupted a hardirq 126 * handler) we can't do that and just have to keep using the 127 * current stack (which is the irq stack already after all) 128 */ 129 if (curctx != irqctx) { 130 u32 *isp; 131 132 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 133 irqctx->tinfo.task = curctx->tinfo.task; 134 irqctx->tinfo.previous_sp = current_stack_pointer; 135 136 /* 137 * Copy the softirq bits in preempt_count so that the 138 * softirq checks work in the hardirq context. 139 */ 140 irqctx->tinfo.preempt_count = 141 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 142 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 143 144 __asm__ __volatile__ ( 145 "mov %0, r4 \n" 146 "mov r15, r8 \n" 147 "jsr @%1 \n" 148 /* swith to the irq stack */ 149 " mov %2, r15 \n" 150 /* restore the stack (ring zero) */ 151 "mov r8, r15 \n" 152 : /* no outputs */ 153 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 154 : "memory", "r0", "r1", "r2", "r3", "r4", 155 "r5", "r6", "r7", "r8", "t", "pr" 156 ); 157 } else 158 #endif 159 generic_handle_irq(irq); 160 161 irq_exit(); 162 163 set_irq_regs(old_regs); 164 return 1; 165 } 166 167 #ifdef CONFIG_IRQSTACKS 168 static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 169 170 static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 171 172 /* 173 * allocate per-cpu stacks for hardirq and for softirq processing 174 */ 175 void irq_ctx_init(int cpu) 176 { 177 union irq_ctx *irqctx; 178 179 if (hardirq_ctx[cpu]) 180 return; 181 182 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 183 irqctx->tinfo.task = NULL; 184 irqctx->tinfo.exec_domain = NULL; 185 irqctx->tinfo.cpu = cpu; 186 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 187 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 188 189 hardirq_ctx[cpu] = irqctx; 190 191 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 192 irqctx->tinfo.task = NULL; 193 irqctx->tinfo.exec_domain = NULL; 194 irqctx->tinfo.cpu = cpu; 195 irqctx->tinfo.preempt_count = 0; 196 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 197 198 softirq_ctx[cpu] = irqctx; 199 200 printk("CPU %u irqstacks, hard=%p soft=%p\n", 201 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 202 } 203 204 void irq_ctx_exit(int cpu) 205 { 206 hardirq_ctx[cpu] = NULL; 207 } 208 209 asmlinkage void do_softirq(void) 210 { 211 unsigned long flags; 212 struct thread_info *curctx; 213 union irq_ctx *irqctx; 214 u32 *isp; 215 216 if (in_interrupt()) 217 return; 218 219 local_irq_save(flags); 220 221 if (local_softirq_pending()) { 222 curctx = current_thread_info(); 223 irqctx = softirq_ctx[smp_processor_id()]; 224 irqctx->tinfo.task = curctx->task; 225 irqctx->tinfo.previous_sp = current_stack_pointer; 226 227 /* build the stack frame on the softirq stack */ 228 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 229 230 __asm__ __volatile__ ( 231 "mov r15, r9 \n" 232 "jsr @%0 \n" 233 /* switch to the softirq stack */ 234 " mov %1, r15 \n" 235 /* restore the thread stack */ 236 "mov r9, r15 \n" 237 : /* no outputs */ 238 : "r" (__do_softirq), "r" (isp) 239 : "memory", "r0", "r1", "r2", "r3", "r4", 240 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 241 ); 242 243 /* 244 * Shouldnt happen, we returned above if in_interrupt(): 245 */ 246 WARN_ON_ONCE(softirq_count()); 247 } 248 249 local_irq_restore(flags); 250 } 251 #endif 252 253 void __init init_IRQ(void) 254 { 255 plat_irq_setup(); 256 257 /* Perform the machine specific initialisation */ 258 if (sh_mv.mv_init_irq) 259 sh_mv.mv_init_irq(); 260 261 irq_ctx_init(smp_processor_id()); 262 } 263 264 #ifdef CONFIG_SPARSE_IRQ 265 int __init arch_probe_nr_irqs(void) 266 { 267 nr_irqs = sh_mv.mv_nr_irqs; 268 return 0; 269 } 270 #endif 271